Repairing Plaster after removing tiles.

Hi,

I am in the process of removing an old backsplash from my kitchen. However when removing the tiles I noticed that quite alot of plaster was coming off with the tiles. I have attached some photos to show you what I mean. Any help with regards to fixing the issue so that I can put on new tiles would be great. Cheers.
https://imgur.com/SYx5N3z
https://imgur.com/koHT7R3